US20050025098A1 - Communication system, transmitter of the system, receiver of the system, and physical layer control method - Google Patents
Communication system, transmitter of the system, receiver of the system, and physical layer control method Download PDFInfo
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- US20050025098A1 US20050025098A1 US10/801,548 US80154804A US2005025098A1 US 20050025098 A1 US20050025098 A1 US 20050025098A1 US 80154804 A US80154804 A US 80154804A US 2005025098 A1 US2005025098 A1 US 2005025098A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
- H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
- H04B7/2628—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA]
- H04B7/264—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] for data rate control
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/30—Definitions, standards or architectural aspects of layered protocol stacks
- H04L69/32—Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
- H04L69/322—Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions
- H04L69/323—Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions in the physical layer [OSI layer 1]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
- H04J13/16—Code allocation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W24/00—Supervisory, monitoring or testing arrangements
Definitions
- the present invention relates to a communication system and, more particularly, to a communication system which executes physical layer control by using spreading codes of a parallel combinatory spread spectrum scheme, a transmitter of the system, a receiver of the system, and a physical layer control method.
- a spread spectrum communication apparatus and spread spectrum communication method are known in association with data communication of a mobile communication system (e.g., Jpn. Pat. Appln. KOKAI Publication No. 9-205412 (p. 4, FIGS. 1 and 2)).
- a mobile communication system e.g., Jpn. Pat. Appln. KOKAI Publication No. 9-205412 (p. 4, FIGS. 1 and 2).
- a communication system which executes data communication of a parallel combinatory spread spectrum scheme between a transmitter and a receiver
- the transmitter comprising: an acquiring unit configured to acquire radio channel quality information by measuring a radio channel quality when the transmitter receives a signal; an information generation unit configured to generate first physical layer control information for control of a physical layer based on the radio channel quality information at a first control timing which fails to be in cooperation with a dedicated channel for the control of the physical layer; and a first transmission unit configured to transmit, to the receiver, the first physical layer control information by selected spreading-code data of the parallel combinatory spread spectrum scheme, and the receiver comprising: a first receiving unit configured to receive the first physical layer control information by the selected spreading-code data of the parallel combinatory spread spectrum scheme; and a physical layer control unit configured to control the physical layer between the receiver and the transmitter based on the first physical layer control information.
- a transmitter comprising: an acquiring unit configured to acquire radio channel quality information by measuring a radio channel quality when the transmitter receives a signal; an information generation unit configured to generate first physical layer control information for control of a physical layer based on the radio channel quality information at a first control timing which fails to be in cooperation with a dedicated channel for the control of the physical layer; and a first transmission unit configured to transmit, to the receiver, the first physical layer control information by selected spreading-code data of a parallel combinatory spread spectrum scheme.
- a receiver comprising: a first receiving unit configured to receive first physical layer control information for control of a physical layer by selected spreading-code data of a parallel combinatory spread spectrum scheme; and a physical layer control unit configured to control the physical layer between the receiver and a transmitter based on the first physical layer control information.
- FIG. 1 is a view showing mapping of spreading codes used in a parallel combinatory spread spectrum scheme according to the embodiment
- FIG. 2 is a block diagram of the main part of a mobile station in a mobile communication system according to the embodiment
- FIG. 3 is a block diagram of the main part of a base station in the mobile communication system according to the embodiment.
- FIG. 4 is a timing chart of downlink transmission data rate control according to the embodiment.
- FIG. 5 is a flow chart showing the operation of the mobile station in the mobile communication system according to the embodiment.
- FIG. 6 is a flow chart showing the operation of the base station in the mobile communication system according to the embodiment.
- FIG. 7 is a timing chart of downlink transmission data rate control.
- the embodiment of the present invention implements, in a communication system contained between a transmitter and a receiver, physical layer control which uses both a dedicated channel and a parallel combinatory spread spectrum scheme.
- FIGS. 1 to 7 show an embodiment of a base station (i.e., a receiver) and a mobile station (i.e., a transmitter) in a communication system according to the embodiment.
- a base station i.e., a receiver
- a mobile station i.e., a transmitter
- FIG. 1 is a view showing the use combination states of spreading codes used in the parallel combinatory spread spectrum scheme.
- the multiple number indicates the number of spreading codes which are used simultaneously.
- “1” is assigned to each of two spreading codes which are simultaneously used in the k spreading codes A, B, C, and D.
- the pattern is “0011”, and 1-bit selected spreading-code data is “1”.
- the pattern is “0101”, and 1-bit selected spreading-code data is “0”.
- the transmitter changes 1-bit selected spreading-code data into a pattern of k spreading codes. This is called “mapping”.
- the receiver detects spreading codes which are simultaneously used and reproduces 1-bit selected spreading-code data from k spreading codes. This is called “demapping”.
- two types of data i.e., spread sequence data and selected spreading-code data can be transmitted from the transmitter to the receiver.
- Selected spreading-code data is transmission data which are divided into two sequences (the C-sequence and D-sequence, or the B-sequence and D-sequence).
- selected spreading-code data is “1”
- the data of the C-sequence and D-sequence are multiplied by the spreading codes C and D.
- a spread signal is generated by adding the products and transmitted.
- selected spreading-code data is “0”
- the data of the B-sequence and D-sequence are multiplied by the spreading codes B and D.
- a spread signal is generated by adding the products and transmitted.
- the spreading codes C and D When the spreading codes C and D are used in the transmitter, the energy levels of the despread results of the spreading codes C and D appear high.
- the spreading codes C and D whose energy levels appear high, the spread sequence data is reproduced.
- the pattern of the combinatory spreading codes of the spreading codes C and D whose energy levels appear high is “0011”. When this pattern is demapped on the basis of the table shown in FIG. 1 , the selected spreading-code data “1” is reproduced. Even when the energy levels of the despread results of the spreading codes B and D appear high upon despread processing, its pattern is demapped, and the selected spreading-code data “0” is reproduced.
- FIG. 2 is a block diagram of the main part of the mobile station.
- the mobile station contains an antenna 1 , radio unit 2 , demodulation unit 3 , downlink transmission data rate control determination unit 4 (information generation unit), modulation unit 5 , and parallel combinatory spread spectrum unit 6 .
- the radio unit 2 is connected to the antenna 1 , demodulation unit 3 , modulation unit 5 , and parallel combinatory spread spectrum unit 6 .
- the demodulation unit 3 is connected to the downlink transmission data rate control determination unit 4 .
- the downlink transmission data rate control determination unit 4 is connected to the modulation unit 5 and parallel combinatory spread spectrum unit 6 .
- the parallel combinatory spread spectrum unit 6 receives spread sequence data input in the mobile station, generates transmission data by the parallel combinatory spread spectrum scheme, and transmits the data to the base station through the radio unit 2 and antenna 1 .
- the parallel combinatory spread spectrum unit 6 contains a mapping unit 7 , spreader 8 , spreading-code generator 9 , and adder 10 .
- Second downlink transmission data rate control information 4 b sent from the downlink transmission data rate control determination unit 4 is supplied to the mapping unit 7 of the parallel combinatory spread spectrum unit 6 as selected spreading-code data 6 b .
- the mapping unit 7 stores the contents of the table shown in FIG. 1 .
- the spreading-code generator 9 sends, to the spreader 8 , a signal 9 a of the spreading code A, a signal 9 b of the spreading code B, a signal 9 c of the spreading code C, and a signal 9 d of the spreading code D in correspondence with the k spreading codes.
- the spreader 8 multiplies spread sequence data 6 a by two spreading codes (e.g., the spreading codes C and D) selected by the mapping data 7 a to spread the data and sends product outputs 8 a and 8 b of two sequences to the adder 10 .
- the adder 10 adds the product outputs 8 a and 8 b of two sequences and sends a sum output 6 c to the radio unit 2 .
- the radio unit 2 executes processing such as up-conversion.
- the spread signal is transmitted from the antenna 1 to the mobile station.
- FIG. 3 is a block diagram of the main part of the base station.
- the base station contains an antenna 51 , radio unit 52 , demodulation unit 53 , adaptive modulator 54 , spread unit 55 , and parallel combinatory spread spectrum unit 56 .
- the radio unit 52 is connected to the antenna 51 , demodulation unit 53 , spread unit 55 , and parallel combinatory spread spectrum unit 56 .
- the demodulation unit 53 is connected to the adaptive modulator 54 .
- the adaptive modulator 54 is connected to the spread unit 55 and parallel combinatory spread spectrum unit 56 .
- the parallel combinatory spread spectrum unit 56 By using the parallel combinatory spread spectrum scheme, the parallel combinatory spread spectrum unit 56 generates spread sequence data from the spread signal received through the antenna 51 and radio unit 52 .
- the parallel combinatory spread spectrum unit 56 contains multipliers 57 , 58 , 59 , and 60 , a spreading-code generator 61 , spreading code determiner 62 , and demapping unit 63 .
- the demapping unit 63 obtains a demapping signal, although it stores the contents of the table shown in FIG. 1 , like the mapping unit 7 of the mobile station.
- the spread signal transmitted from the mobile station is received by the radio unit 52 through the antenna 51 .
- the radio unit 52 executes processing such as down-conversion and sends an output signal 52 a to the multipliers 57 , 58 , 59 , and 60 of the parallel combinatory spread spectrum unit 56 .
- Each of the multipliers 57 , 58 , 59 , and 60 multiplies the signal 52 a by a corresponding one of the spreading codes A, B, C, and D to execute despread processing.
- Signals 57 a , 58 a , 59 a , and 60 a are sent to the spreading code determiner 62 .
- the spreading code determiner 62 checks the energy levels of the signals 57 a , 58 a , 59 a , and 60 a . For example, when the multiple number is “2”, the energy levels of the multipliers 59 and 60 (or 58 and 60 ) corresponding to two spreading codes (the spreading codes C and D or B and D) appear high. The spreading code determiner 62 compares the energy levels of the output signals 57 a , 58 a , 59 a , and 60 a from the multipliers 57 , 58 , 59 , and 60 and determines the two spreading codes used on the mobile station side.
- the spreading code determiner 62 despreads the outputs from the multipliers corresponding to the two determined spreading codes to reproduce spread sequence data 62 a.
- the two determined spreading codes are sent from the spreading code determiner 62 to the demapping unit 63 .
- the demapping unit 63 determines the spreading code combination from the two spreading codes and executes demapping on the basis of the table shown in FIG. 1 to reproduce selected spreading-code data 63 a.
- Downlink transmission data rate control as one of physical layer control operations between the base station and the mobile station will be described next by using selected spreading-code data of the parallel combinatory spread spectrum scheme.
- FIG. 4 is a timing chart showing downlink transmission data rate control.
- FIG. 5 is a flow chart of the downlink transmission data rate control of the mobile station.
- FIG. 6 is a flow chart of the downlink transmission data rate control of the base station.
- FIG. 7 is a timing chart showing downlink transmission data rate control.
- a downlink SIR (Signal-to-Interference Ratio) 3 a indicated by the dotted line in FIG. 4 is a measurement value representing the downlink radio propagation circumstance quality from the base station to the mobile station.
- the waveform normally varies.
- the downlink transmission data rate is controlled as indicated by the solid line.
- the downlink transmission data rate control two types of control are executed in accordance with timings.
- One of downlink transmission data rate control by a dedicated channel for physical layer control which corresponds to timings T 10 , T 20 , and T 30 in FIG. 4 .
- the other is downlink transmission data rate control by selected spreading-code data of the parallel combinatory spread spectrum scheme, which corresponds to timings T 11 , T 12 , T 13 , T 14 , T 15 , T 21 , T 22 , T 23 , T 24 , and T 25 in the intervals between the timings T 10 , T 20 , and T 30 .
- the demodulation unit 3 of the mobile station calculates the downlink SIR 3 a by measuring the reception power of a common pilot signal which is normally transmitted from the base station to the mobile station. More specifically, the common pilot signal from the base station is received by the radio unit 2 through the antenna 1 . The radio unit 2 executes processing such as down-conversion for the received common pilot signal and sends a signal 2 a to the demodulation unit 3 . The demodulation unit 3 demodulates the received signal 2 a . The demodulation unit 3 also calculates the downlink SIR 3 a by measuring the reception power of the common pilot signal and sends the downlink SIR 3 a to the downlink transmission data rate control determination unit 4 (step S 1 ).
- the downlink transmission data rate control determination unit 4 confirms the slot timing shown in the timing chart in FIG. 4 (step S 2 ).
- the downlink transmission data rate control determination unit 4 sets the downlink transmission data rate directly corresponding to the downlink SIR 3 a to first downlink transmission data rate control information 4 a (step S 3 ). More specifically, at the timing T 10 , rate 10 is set as the first downlink transmission data rate control information 4 a corresponding to SIR 10 .
- rate 20 is set as the first downlink transmission data rate control information 4 a corresponding to SIR 20 .
- rate 30 is set as the first downlink transmission data rate control information 4 a corresponding to SIR 30 .
- the first downlink transmission data rate control information 4 a generated by the downlink transmission data rate control determination unit 4 is sent to the modulation unit 5 serving as a dedicated channel for physical layer control.
- the modulation unit 5 executes modulation processing and sends a modulated signal 5 a to the radio unit 2 .
- the radio unit 2 Upon receiving the modulated signal 5 a, the radio unit 2 executes processing such as up-conversion and transmits the signal from the antenna 1 to the base station.
- step S 2 at the second control timing (T 11 , T 12 , T 13 , T 14 , T 15 , T 21 , T 22 , T 23 , T 24 , or T 25 ), the downlink transmission data rate control determination unit 4 compares the downlink SIR 3 a at each timing with the downlink SIR 3 a at the immediately preceding timing (step S 4 ). If the downlink SIR 3 a at each timing is larger than that at the immediately preceding timing, the downlink transmission data rate control determination unit 4 sends, to the parallel combinatory spread spectrum unit 6 as the second downlink transmission data rate control information 4 b , “unit control amount up” which increases the downlink transmission data rate by a unit control amount.
- the downlink SIR 3 a (SIR 11 ) at the timing T 11 is larger than the downlink SIR 3 a (SIR 10 ) at the immediately preceding timing T 10 .
- a downlink transmission data rate increased by the unit control amount is set.
- the “unit control amount up” is executed at the timings T 11 , T 21 , T 22 , T 23 , T 24 , and T 25 .
- the second downlink transmission data rate control information 4 b is sent to the mapping unit 7 of the parallel combinatory spread spectrum unit 6 as the selected spreading-code data 6 b .
- the mapping unit 7 maps the selected spreading-code data on the basis of the combination of spreading codes in the table shown in FIG. 1 .
- the signal 6 c spread by the parallel combinatory spread spectrum unit 6 is radio-processed by the radio unit 2 and transmitted from the antenna 1 to the base station (step S 5 ).
- step S 4 If it is determined in step S 4 that the downlink SIR 3 a at each timing is smaller than that at the immediately preceding timing, the downlink transmission data rate control determination unit 4 sends, to the parallel combinatory spread spectrum unit 6 as the second downlink transmission data rate control information 4 b , “unit control amount down” which decreases the downlink transmission data rate by the unit control amount.
- the downlink SIR 3 a (SIR 12 ) at the timing T 12 is smaller than the downlink SIR 3 a (SIR 11 ) at the immediately preceding timing T 11 .
- a downlink transmission data rate decreased by the unit control amount is set.
- the “unit control amount down” is executed at the timings T 12 to T 15 .
- the signal 6 c spread by the parallel combinatory spread spectrum unit 6 is radio-processed by the radio unit 2 and transmitted from the antenna 1 to the base station (step S 6 ).
- the downlink transmission data rate control in the base station shown in FIG. 3 which has received the first and second downlink transmission data rate control information, will be described next with reference to the flow chart in FIG. 6 .
- the first downlink transmission data rate control information 4 a is received by the radio unit 52 through the antenna 51 , subjected to processing such as down-conversion, and sent to the demodulation unit 53 serving as a dedicated channel for physical layer control.
- the demodulation unit 53 executes demodulation to reproduce the first downlink transmission data rate control information 4 a and sends it to the adaptive modulator 54 as first downlink transmission data rate control information 53 a.
- the parallel combinatory spread spectrum unit 56 executes despread processing to reproduce the selected spreading-code data 63 a .
- the second downlink transmission data rate control information 4 b is reproduced and sent to the adaptive modulator 54 as second downlink transmission data rate control information 63 b.
- the adaptive modulator 54 executes processing in accordance with the radio channel quality. More specifically, when the radio channel quality is high, the adaptive modulator 54 sets the transmission data 54 a to a high rate. When the radio channel quality is poor, the adaptive modulator 54 sets the transmission data 54 a to a low rate.
- the adaptive modulator 54 checks the incoming call situation of the channel (step S 51 ). When an incoming call from the demodulation unit 53 serving as a dedicated channel is detected, the first downlink transmission data rate control information 53 a is received (step S 52 ). The adaptive modulator 54 sends the transmission data 54 a to the spread unit 55 at the designated rate of the first downlink transmission data rate control information 53 a (step S 53 ). The spread unit 55 spreads a signal 54 b and transmits it to the radio unit 52 . The radio unit 52 executes processing such as up-conversion and transmits the signal from the antenna 51 to the mobile station. The timings T 10 , T 20 , and T 30 correspond to this processing. The arrangement and operation of the spread unit 55 are the same as those of the parallel combinatory spread spectrum unit 6 shown in FIG. 2 , and a description thereof will be omitted.
- the adaptive modulator 54 receives the second downlink transmission data rate control information 63 b (step S 54 ). The adaptive modulator 54 determines whether the second downlink transmission data rate control information 63 b should be subjected to “unit control amount up” or “unit control amount down” (step S 55 ).
- the adaptive modulator 54 sends the transmission data 54 a to the spread unit 55 at a rate obtained by increasing the transmission data rate at the immediately preceding timing by the unit control amount (step S 56 ).
- the spread unit 55 executes spread processing.
- the radio unit 52 executes up-conversion processing.
- the data is transmitted from the antenna 51 to the mobile station.
- the timings T 11 , T 21 , T 22 , T 23 , T 24 , and T 25 correspond to this processing.
- step S 55 If it is determined in step S 55 that “unit control amount down” should be executed, the adaptive modulator 54 sends the transmission data 54 a to the spread unit 55 at a rate obtained by decreasing the transmission data rate at the immediately preceding timing by the unit control amount (step S 57 ).
- the spread unit 55 executes spread processing.
- the radio unit 52 executes up-conversion processing.
- the data is transmitted from the antenna 51 to the mobile station as an adaptive modulated signal.
- the timings T 12 , T 13 , T 14 , and T 15 correspond to this processing.
- the adaptive modulated signal from the base station is received by the radio unit 2 through the antenna 1 , subjected to processing such as down-conversion, and sent to a spread unit 11 .
- the spread unit 11 executes despread processing to obtain reception data 11 a so that the transmission data 54 a transmitted from the base station is reproduced.
- the arrangement and operation of the spread unit 11 are the same as those of the parallel combinatory spread spectrum unit 56 shown in FIG. 3 , and a description thereof will be omitted.
- the mobile station repeatedly executes the operation shown in FIG. 5 .
- the base station repeatedly executes the operation shown in FIG. 6 .
- the downlink transmission data rate control shown in FIG. 4 is thus executed.
- FIG. 7 is a timing chart showing downlink transmission data rate control when only the first downlink transmission data rate control information 4 a as the dedicated channel information of physical layer control is used.
- a downlink transmission data rate indicated by the solid line is obtained.
- the downlink radio propagation circumstances always vary as the mobile station moves. Accordingly, the downlink SIR 3 a also always varies. For this reason, the hatched portion shown in FIG. 7 is the difference between the downlink SIR and the downlink transmission data rate. If this difference is large, the downlink transmission data rate is too high. A transmission error of the transmission data 54 a transmitted from the base station to the mobile station may occur, or conversely, the downlink transmission data rate is suppressed low.
- the hatched portion representing the difference between the downlink SIR and the downlink transmission data rate can be made small.
- fine downlink transmission data rate control corresponding to the change in downlink radio propagation circumstances can be executed.
- the base station or mobile station can maintain compatibility.
- the transmission data rate can directly be designed instead of designating unit control amount up/down.
- the downlink SIR is measured, and a transmission data rate corresponding to it is directly determined.
- the number of different transmission data rates is increased by increasing the combinations of spreading codes shown in FIG. 1 as transmission data rate information, and selected spreading-code data is mapped onto the transmission data rate information.
- downlink transmission data rate control as one of physical layer control information has been described.
- the same control as described above can be executed even for transmission power control corresponding to a change in radio propagation circumstances.
- the base station transmits the uplink transmission power control information of physical layer control information by selected spreading-code data, and the mobile station receives this information. If uplink transmission power control is executed by using a dedicated channel to quickly cope with an abrupt change in radio propagation circumstances, an adverse effect on radio resources is generated. However, when selected spreading-code data is used, the adverse effect on radio resources can be prevented.
- the embodiment is suitable not only for the mobile communication system but also for wireless LAN or any other communication system which executes data communication of the parallel combinatory spread spectrum scheme.
- the embodiment can be applied to a transmitter and receiver in a wireless LAN or any other communication system.
- the parallel spread spectrum method fundamentally executes transmission of spread sequence data.
- selected spreading-code data no special channel need be used, and any influence on radio resources can be prevented.
- the system can cope with an abrupt change in radio propagation circumstances.
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Abstract
Communication system which executes data communication of parallel combinatory spread spectrum scheme between transmitter and receiver, transmitter comprising acquiring unit which acquires radio channel quality information by measuring radio channel quality when transmitter receives signal, information generation unit which generates first physical layer control information for control of physical layer based on radio channel quality information at first control timing which fails to be in cooperation with dedicated channel for control of physical layer, and first transmission unit which transmits, to receiver, first physical layer control information by selected spreading-code data of parallel combinatory spread spectrum scheme, and receiver comprising first receiving unit which receives first physical layer control information by selected spreading-code data of parallel combinatory spread spectrum scheme, and physical layer control unit controls physical layer between receiver and transmitter based on first physical layer control information.
Description
- This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-199295, filed Jul. 18, 2003, the entire contents of which are incorporated herein by reference.
- 1. Field of the Invention
- The present invention relates to a communication system and, more particularly, to a communication system which executes physical layer control by using spreading codes of a parallel combinatory spread spectrum scheme, a transmitter of the system, a receiver of the system, and a physical layer control method.
- 2. Description of the Related Art
- A spread spectrum communication apparatus and spread spectrum communication method are known in association with data communication of a mobile communication system (e.g., Jpn. Pat. Appln. KOKAI Publication No. 9-205412 (p. 4, FIGS. 1 and 2)).
- In the spread spectrum communication method described in
patent reference 1, primary communication data to be subjected to modulation and spread processing and secondary communication data which adds a code to a combination of a plurality of spreading codes are prepared. - For this conventional apparatus, however, there is no description of any detailed technique about how to use the secondary communication data which adds a code to a combination of a plurality of spreading codes.
- It is an object of the present invention to provide a communication system using a spread spectrum communication method which exploits the high communication speed of secondary communication data and the application purpose of sub-communication information, a transmitter of the system, a receiver of the system, and a physical layer control method.
- According to a first aspect of the invention, there is provided a communication system which executes data communication of a parallel combinatory spread spectrum scheme between a transmitter and a receiver, the transmitter comprising: an acquiring unit configured to acquire radio channel quality information by measuring a radio channel quality when the transmitter receives a signal; an information generation unit configured to generate first physical layer control information for control of a physical layer based on the radio channel quality information at a first control timing which fails to be in cooperation with a dedicated channel for the control of the physical layer; and a first transmission unit configured to transmit, to the receiver, the first physical layer control information by selected spreading-code data of the parallel combinatory spread spectrum scheme, and the receiver comprising: a first receiving unit configured to receive the first physical layer control information by the selected spreading-code data of the parallel combinatory spread spectrum scheme; and a physical layer control unit configured to control the physical layer between the receiver and the transmitter based on the first physical layer control information.
- According to a second aspect of the invention, there is provided a transmitter comprising: an acquiring unit configured to acquire radio channel quality information by measuring a radio channel quality when the transmitter receives a signal; an information generation unit configured to generate first physical layer control information for control of a physical layer based on the radio channel quality information at a first control timing which fails to be in cooperation with a dedicated channel for the control of the physical layer; and a first transmission unit configured to transmit, to the receiver, the first physical layer control information by selected spreading-code data of a parallel combinatory spread spectrum scheme.
- According to a third aspect of the invention, there is provided a receiver comprising: a first receiving unit configured to receive first physical layer control information for control of a physical layer by selected spreading-code data of a parallel combinatory spread spectrum scheme; and a physical layer control unit configured to control the physical layer between the receiver and a transmitter based on the first physical layer control information.
- Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
- The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
-
FIG. 1 is a view showing mapping of spreading codes used in a parallel combinatory spread spectrum scheme according to the embodiment; -
FIG. 2 is a block diagram of the main part of a mobile station in a mobile communication system according to the embodiment; -
FIG. 3 is a block diagram of the main part of a base station in the mobile communication system according to the embodiment; -
FIG. 4 is a timing chart of downlink transmission data rate control according to the embodiment; -
FIG. 5 is a flow chart showing the operation of the mobile station in the mobile communication system according to the embodiment; -
FIG. 6 is a flow chart showing the operation of the base station in the mobile communication system according to the embodiment; and -
FIG. 7 is a timing chart of downlink transmission data rate control. - The embodiment of the present invention implements, in a communication system contained between a transmitter and a receiver, physical layer control which uses both a dedicated channel and a parallel combinatory spread spectrum scheme.
- FIGS. 1 to 7 show an embodiment of a base station (i.e., a receiver) and a mobile station (i.e., a transmitter) in a communication system according to the embodiment.
- The parallel combinatory spread spectrum scheme will be described first with reference to FIGS. 1 to 3.
FIG. 1 is a view showing the use combination states of spreading codes used in the parallel combinatory spread spectrum scheme. In the example shown inFIG. 1 , a number k of assignment spreading codes is “4”, i.e., k (=4) spreading codes A, B, C, and D are used, and the multiple number is “2”. The multiple number indicates the number of spreading codes which are used simultaneously. - More specifically, in the field “spreading codes” shown in
FIG. 1 , “1” is assigned to each of two spreading codes which are simultaneously used in the k spreading codes A, B, C, and D. For example, when the spreading codes C and D are simultaneously used, the pattern is “0011”, and 1-bit selected spreading-code data is “1”. When the spreading codes B and D are simultaneously used, the pattern is “0101”, and 1-bit selected spreading-code data is “0”. - The transmitter changes 1-bit selected spreading-code data into a pattern of k spreading codes. This is called “mapping”. On the other hand, the receiver detects spreading codes which are simultaneously used and reproduces 1-bit selected spreading-code data from k spreading codes. This is called “demapping”.
- In the parallel combinatory spread spectrum scheme, two types of data, i.e., spread sequence data and selected spreading-code data can be transmitted from the transmitter to the receiver.
- For example, in the transmitter, when selected spreading-code data is “1”, it is mapped onto the pattern “0011” in which the spreading codes C and D are simultaneously used. When selected spreading-code data is “0”, it is mapped onto the pattern “0101” in which the spreading codes B and D are simultaneously used. Selected spreading-code data is transmission data which are divided into two sequences (the C-sequence and D-sequence, or the B-sequence and D-sequence). When selected spreading-code data is “1”, the data of the C-sequence and D-sequence are multiplied by the spreading codes C and D. A spread signal is generated by adding the products and transmitted. When selected spreading-code data is “0”, the data of the B-sequence and D-sequence are multiplied by the spreading codes B and D. A spread signal is generated by adding the products and transmitted.
- On the other hand, in the receiver, when the spread signal from the transmitter is received, the spread signal is multiplied by each of the k (=4) spreading codes A, B, C, and D to execute despread. When the spreading codes C and D are used in the transmitter, the energy levels of the despread results of the spreading codes C and D appear high. By using the spreading codes C and D whose energy levels appear high, the spread sequence data is reproduced. The pattern of the combinatory spreading codes of the spreading codes C and D whose energy levels appear high is “0011”. When this pattern is demapped on the basis of the table shown in
FIG. 1 , the selected spreading-code data “1” is reproduced. Even when the energy levels of the despread results of the spreading codes B and D appear high upon despread processing, its pattern is demapped, and the selected spreading-code data “0” is reproduced. -
FIG. 2 is a block diagram of the main part of the mobile station. The mobile station contains anantenna 1,radio unit 2,demodulation unit 3, downlink transmission data rate control determination unit 4 (information generation unit),modulation unit 5, and parallel combinatoryspread spectrum unit 6. Theradio unit 2 is connected to theantenna 1,demodulation unit 3,modulation unit 5, and parallel combinatoryspread spectrum unit 6. Thedemodulation unit 3 is connected to the downlink transmission data ratecontrol determination unit 4. The downlink transmission data ratecontrol determination unit 4 is connected to themodulation unit 5 and parallel combinatoryspread spectrum unit 6. - The parallel combinatory
spread spectrum unit 6 receives spread sequence data input in the mobile station, generates transmission data by the parallel combinatory spread spectrum scheme, and transmits the data to the base station through theradio unit 2 andantenna 1. The parallel combinatoryspread spectrum unit 6 contains a mapping unit 7, spreader 8, spreading-code generator 9, andadder 10. - Second downlink transmission data
rate control information 4 b sent from the downlink transmission data ratecontrol determination unit 4 is supplied to the mapping unit 7 of the parallel combinatoryspread spectrum unit 6 as selected spreading-code data 6 b. The mapping unit 7 stores the contents of the table shown inFIG. 1 . Hence, the mapping unit 7 maps the selected spreading-code data onto a pattern of the k (=4) spreading codes A, B, C, and D on the basis of the contents of the selected spreading-code data 6 b and sendsmapping data 7 a to the spreader 8. The spreading-code generator 9 sends, to the spreader 8, a signal 9 a of the spreading code A, a signal 9 b of the spreading code B, a signal 9 c of the spreading code C, and a signal 9 d of the spreading code D in correspondence with the k spreading codes. - The spreader 8 multiplies spread
sequence data 6 a by two spreading codes (e.g., the spreading codes C and D) selected by themapping data 7 a to spread the data and sendsproduct outputs adder 10. Theadder 10 adds theproduct outputs sum output 6 c to theradio unit 2. Theradio unit 2 executes processing such as up-conversion. The spread signal is transmitted from theantenna 1 to the mobile station. - The arrangement and operation of the base station which receives the spread signal will be described next.
-
FIG. 3 is a block diagram of the main part of the base station. The base station contains anantenna 51,radio unit 52,demodulation unit 53,adaptive modulator 54, spreadunit 55, and parallel combinatoryspread spectrum unit 56. Theradio unit 52 is connected to theantenna 51,demodulation unit 53, spreadunit 55, and parallel combinatoryspread spectrum unit 56. Thedemodulation unit 53 is connected to theadaptive modulator 54. Theadaptive modulator 54 is connected to thespread unit 55 and parallel combinatoryspread spectrum unit 56. - By using the parallel combinatory spread spectrum scheme, the parallel combinatory
spread spectrum unit 56 generates spread sequence data from the spread signal received through theantenna 51 andradio unit 52. The parallel combinatoryspread spectrum unit 56 containsmultipliers code generator 61, spreadingcode determiner 62, anddemapping unit 63. Thedemapping unit 63 obtains a demapping signal, although it stores the contents of the table shown inFIG. 1 , like the mapping unit 7 of the mobile station. - In the base station having the above arrangement, the spread signal transmitted from the mobile station is received by the
radio unit 52 through theantenna 51. Theradio unit 52 executes processing such as down-conversion and sends anoutput signal 52 a to themultipliers spread spectrum unit 56. The spreading-code generator 61 of the parallel combinatoryspread spectrum unit 56 generates asignal 61 a of the spreading code A, asignal 61 b of the spreading code B, asignal 61 c of the spreading code C, and asignal 61 d of the spreading code D in correspondence with the k (=4) spreading codes and sends each signal to a corresponding one of themultipliers - Each of the
multipliers signal 52 a by a corresponding one of the spreading codes A, B, C, and D to execute despread processing.Signals code determiner 62. - The spreading
code determiner 62 checks the energy levels of thesignals multipliers 59 and 60 (or 58 and 60) corresponding to two spreading codes (the spreading codes C and D or B and D) appear high. The spreadingcode determiner 62 compares the energy levels of the output signals 57 a, 58 a, 59 a, and 60 a from themultipliers - The spreading
code determiner 62 despreads the outputs from the multipliers corresponding to the two determined spreading codes to reproduce spreadsequence data 62 a. - The two determined spreading codes are sent from the spreading
code determiner 62 to thedemapping unit 63. Thedemapping unit 63 determines the spreading code combination from the two spreading codes and executes demapping on the basis of the table shown inFIG. 1 to reproduce selected spreading-code data 63 a. - Downlink transmission data rate control as one of physical layer control operations between the base station and the mobile station will be described next by using selected spreading-code data of the parallel combinatory spread spectrum scheme.
-
FIG. 4 is a timing chart showing downlink transmission data rate control.FIG. 5 is a flow chart of the downlink transmission data rate control of the mobile station.FIG. 6 is a flow chart of the downlink transmission data rate control of the base station.FIG. 7 is a timing chart showing downlink transmission data rate control. - A downlink SIR (Signal-to-Interference Ratio) 3 a indicated by the dotted line in
FIG. 4 is a measurement value representing the downlink radio propagation circumstance quality from the base station to the mobile station. The waveform normally varies. In correspondence with the variation, the downlink transmission data rate is controlled as indicated by the solid line. - As the downlink transmission data rate control, two types of control are executed in accordance with timings. One of downlink transmission data rate control by a dedicated channel for physical layer control, which corresponds to timings T10, T20, and T30 in
FIG. 4 . The other is downlink transmission data rate control by selected spreading-code data of the parallel combinatory spread spectrum scheme, which corresponds to timings T11, T12, T13, T14, T15, T21, T22, T23, T24, and T25 in the intervals between the timings T10, T20, and T30. - The downlink transmission data rate control in the mobile station shown in
FIG. 4 will be described next with reference toFIG. 5 . - The
demodulation unit 3 of the mobile station calculates thedownlink SIR 3 a by measuring the reception power of a common pilot signal which is normally transmitted from the base station to the mobile station. More specifically, the common pilot signal from the base station is received by theradio unit 2 through theantenna 1. Theradio unit 2 executes processing such as down-conversion for the received common pilot signal and sends asignal 2 a to thedemodulation unit 3. Thedemodulation unit 3 demodulates the receivedsignal 2 a. Thedemodulation unit 3 also calculates thedownlink SIR 3 a by measuring the reception power of the common pilot signal and sends thedownlink SIR 3 a to the downlink transmission data rate control determination unit 4 (step S1). - The downlink transmission data rate
control determination unit 4 confirms the slot timing shown in the timing chart inFIG. 4 (step S2). At the first control timing (T10, T20, or T30), the downlink transmission data ratecontrol determination unit 4 sets the downlink transmission data rate directly corresponding to thedownlink SIR 3 a to first downlink transmission datarate control information 4 a (step S3). More specifically, at the timing T10,rate 10 is set as the first downlink transmission datarate control information 4 a corresponding toSIR 10. At the timing T20,rate 20 is set as the first downlink transmission datarate control information 4 a corresponding toSIR 20. At the timing T30,rate 30 is set as the first downlink transmission datarate control information 4 a corresponding toSIR 30. - The first downlink transmission data
rate control information 4 a generated by the downlink transmission data ratecontrol determination unit 4 is sent to themodulation unit 5 serving as a dedicated channel for physical layer control. Themodulation unit 5 executes modulation processing and sends a modulatedsignal 5 a to theradio unit 2. Upon receiving the modulatedsignal 5 a, theradio unit 2 executes processing such as up-conversion and transmits the signal from theantenna 1 to the base station. - In step S2, at the second control timing (T11, T12, T13, T14, T15, T21, T22, T23, T24, or T25), the downlink transmission data rate
control determination unit 4 compares thedownlink SIR 3 a at each timing with thedownlink SIR 3 a at the immediately preceding timing (step S4). If thedownlink SIR 3 a at each timing is larger than that at the immediately preceding timing, the downlink transmission data ratecontrol determination unit 4 sends, to the parallel combinatoryspread spectrum unit 6 as the second downlink transmission datarate control information 4 b, “unit control amount up” which increases the downlink transmission data rate by a unit control amount. For example, thedownlink SIR 3 a (SIR 11) at the timing T11 is larger than thedownlink SIR 3 a (SIR 10) at the immediately preceding timing T10. Hence, a downlink transmission data rate increased by the unit control amount is set. For thedownlink SIRs 3 a shown inFIG. 4 , the “unit control amount up” is executed at the timings T11, T21, T22, T23, T24, and T25. - The second downlink transmission data
rate control information 4 b is sent to the mapping unit 7 of the parallel combinatoryspread spectrum unit 6 as the selected spreading-code data 6 b. The mapping unit 7 maps the selected spreading-code data on the basis of the combination of spreading codes in the table shown inFIG. 1 . Thesignal 6 c spread by the parallel combinatoryspread spectrum unit 6 is radio-processed by theradio unit 2 and transmitted from theantenna 1 to the base station (step S5). - If it is determined in step S4 that the
downlink SIR 3 a at each timing is smaller than that at the immediately preceding timing, the downlink transmission data ratecontrol determination unit 4 sends, to the parallel combinatoryspread spectrum unit 6 as the second downlink transmission datarate control information 4 b, “unit control amount down” which decreases the downlink transmission data rate by the unit control amount. For example, thedownlink SIR 3 a (SIR 12) at the timing T12 is smaller than thedownlink SIR 3 a (SIR 11) at the immediately preceding timing T11. Hence, a downlink transmission data rate decreased by the unit control amount is set. For thedownlink SIRs 3 a shown inFIG. 4 , the “unit control amount down” is executed at the timings T12 to T15. Thesignal 6 c spread by the parallel combinatoryspread spectrum unit 6 is radio-processed by theradio unit 2 and transmitted from theantenna 1 to the base station (step S6). - The downlink transmission data rate control in the base station shown in
FIG. 3 , which has received the first and second downlink transmission data rate control information, will be described next with reference to the flow chart inFIG. 6 . - In base station, the first downlink transmission data
rate control information 4 a is received by theradio unit 52 through theantenna 51, subjected to processing such as down-conversion, and sent to thedemodulation unit 53 serving as a dedicated channel for physical layer control. Thedemodulation unit 53 executes demodulation to reproduce the first downlink transmission datarate control information 4 a and sends it to theadaptive modulator 54 as first downlink transmission datarate control information 53 a. - When the second downlink transmission data
rate control information 4 b is received by theradio unit 52 through theantenna 51, the parallel combinatoryspread spectrum unit 56 executes despread processing to reproduce the selected spreading-code data 63 a. In addition, the second downlink transmission datarate control information 4 b is reproduced and sent to theadaptive modulator 54 as second downlink transmission datarate control information 63 b. -
Transmission data 54 a to the mobile station, which is input to theadaptive modulator 54, is subjected to adaptive modulation control (physical layer control). Theadaptive modulator 54 executes processing in accordance with the radio channel quality. More specifically, when the radio channel quality is high, theadaptive modulator 54 sets thetransmission data 54 a to a high rate. When the radio channel quality is poor, theadaptive modulator 54 sets thetransmission data 54 a to a low rate. - The
adaptive modulator 54 checks the incoming call situation of the channel (step S51). When an incoming call from thedemodulation unit 53 serving as a dedicated channel is detected, the first downlink transmission datarate control information 53 a is received (step S52). Theadaptive modulator 54 sends thetransmission data 54 a to thespread unit 55 at the designated rate of the first downlink transmission datarate control information 53 a (step S53). Thespread unit 55 spreads asignal 54 b and transmits it to theradio unit 52. Theradio unit 52 executes processing such as up-conversion and transmits the signal from theantenna 51 to the mobile station. The timings T10, T20, and T30 correspond to this processing. The arrangement and operation of thespread unit 55 are the same as those of the parallel combinatoryspread spectrum unit 6 shown inFIG. 2 , and a description thereof will be omitted. - On the other hand, when arrival of the selected spreading-
code data 63 a is detected in step S51, theadaptive modulator 54 receives the second downlink transmission datarate control information 63 b (step S54). Theadaptive modulator 54 determines whether the second downlink transmission datarate control information 63 b should be subjected to “unit control amount up” or “unit control amount down” (step S55). - For “unit control amount up”, the
adaptive modulator 54 sends thetransmission data 54 a to thespread unit 55 at a rate obtained by increasing the transmission data rate at the immediately preceding timing by the unit control amount (step S56). Thespread unit 55 executes spread processing. In addition, theradio unit 52 executes up-conversion processing. The data is transmitted from theantenna 51 to the mobile station. The timings T11, T21, T22, T23, T24, and T25 correspond to this processing. - If it is determined in step S55 that “unit control amount down” should be executed, the
adaptive modulator 54 sends thetransmission data 54 a to thespread unit 55 at a rate obtained by decreasing the transmission data rate at the immediately preceding timing by the unit control amount (step S57). Thespread unit 55 executes spread processing. In addition, theradio unit 52 executes up-conversion processing. The data is transmitted from theantenna 51 to the mobile station as an adaptive modulated signal. The timings T12, T13, T14, and T15 correspond to this processing. - The operation in the mobile station which has received the adaptive modulated signal will be described next. In the mobile station, the adaptive modulated signal from the base station is received by the
radio unit 2 through theantenna 1, subjected to processing such as down-conversion, and sent to aspread unit 11. Thespread unit 11 executes despread processing to obtainreception data 11 a so that thetransmission data 54 a transmitted from the base station is reproduced. - The arrangement and operation of the
spread unit 11 are the same as those of the parallel combinatoryspread spectrum unit 56 shown inFIG. 3 , and a description thereof will be omitted. - The mobile station repeatedly executes the operation shown in
FIG. 5 . The base station repeatedly executes the operation shown inFIG. 6 . The downlink transmission data rate control shown inFIG. 4 is thus executed. -
FIG. 7 is a timing chart showing downlink transmission data rate control when only the first downlink transmission datarate control information 4 a as the dedicated channel information of physical layer control is used. - Since control for the timings T10, T20, and T30 is executed, a downlink transmission data rate indicated by the solid line is obtained. The downlink radio propagation circumstances always vary as the mobile station moves. Accordingly, the
downlink SIR 3 a also always varies. For this reason, the hatched portion shown inFIG. 7 is the difference between the downlink SIR and the downlink transmission data rate. If this difference is large, the downlink transmission data rate is too high. A transmission error of thetransmission data 54 a transmitted from the base station to the mobile station may occur, or conversely, the downlink transmission data rate is suppressed low. - As compared to this, in downlink transmission data rate control which uses both the first downlink transmission data
rate control information 4 a as the dedicated channel information of physical layer control and the second downlink transmission datarate control information 4 b as the selected spreading-code data of the parallel combinatory spread spectrum scheme shown inFIG. 4 , the hatched portion representing the difference between the downlink SIR and the downlink transmission data rate can be made small. Hence, fine downlink transmission data rate control corresponding to the change in downlink radio propagation circumstances can be executed. - Even in a mobile communication system using only the first downlink transmission data
rate control information 4 a as the dedicated channel information of physical layer control, the base station or mobile station can maintain compatibility. - When the second downlink transmission data
rate control information 4 b as selected spreading-code data is used, the transmission data rate can directly be designed instead of designating unit control amount up/down. To do this, the downlink SIR is measured, and a transmission data rate corresponding to it is directly determined. In this case, the number of different transmission data rates is increased by increasing the combinations of spreading codes shown inFIG. 1 as transmission data rate information, and selected spreading-code data is mapped onto the transmission data rate information. - In the above-described embodiment, downlink transmission data rate control as one of physical layer control information has been described. However, the same control as described above can be executed even for transmission power control corresponding to a change in radio propagation circumstances. In uplink transmission power control, the base station transmits the uplink transmission power control information of physical layer control information by selected spreading-code data, and the mobile station receives this information. If uplink transmission power control is executed by using a dedicated channel to quickly cope with an abrupt change in radio propagation circumstances, an adverse effect on radio resources is generated. However, when selected spreading-code data is used, the adverse effect on radio resources can be prevented.
- The embodiment is suitable not only for the mobile communication system but also for wireless LAN or any other communication system which executes data communication of the parallel combinatory spread spectrum scheme. The embodiment can be applied to a transmitter and receiver in a wireless LAN or any other communication system.
- As described above, the parallel spread spectrum method fundamentally executes transmission of spread sequence data. When selected spreading-code data is used, no special channel need be used, and any influence on radio resources can be prevented. In addition, since high-speed processing is possible, the system can cope with an abrupt change in radio propagation circumstances.
- Hence, when both the dedicated channel and the selected spreading-code data are used, fine physical layer control can be executed.
- Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the embodiment in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
Claims (14)
1. A communication system which executes data communication of a parallel combinatory spread spectrum scheme between a transmitter and a receiver,
the transmitter comprising:
an acquiring unit configured to acquire radio channel quality information by measuring a radio channel quality when the transmitter receives a signal;
an information generation unit configured to generate first physical layer control information for control of a physical layer based on the radio channel quality information at a first control timing which fails to be in cooperation with a dedicated channel for the control of the physical layer; and
a first transmission unit configured to transmit, to the receiver, the first physical layer control information by selected spreading-code data of the parallel combinatory spread spectrum scheme, and
the receiver comprising:
a first receiving unit configured to receive the first physical layer control information by the selected spreading-code data of the parallel combinatory spread spectrum scheme; and
a physical layer control unit configured to control the physical layer between the receiver and the transmitter based on the first physical layer control information.
2. The system according to claim 1 , wherein if the radio channel quality measured in generating the first physical layer control information is higher than radio channel quality at an immediately preceding timing, the information generation unit generates the first physical layer control information which increases the control of the physical layer by a unit control amount, and if the radio channel quality measured in generating the first physical layer control information is poorer than the radio channel quality at the immediately preceding timing, the information generation unit generates the first physical layer control information which decreases the control of the physical layer by the unit control amount.
3. The system according to claim 1 , wherein the information generation unit generates the first physical layer control information in correspondence with the radio channel quality information.
4. The system according to claim 1 , wherein the acquiring unit acquires, as the radio channel quality information, SIR (Signal-to-Interference Ratio) information which is obtained by measuring a receiving power of a common pilot signal transmitted from the receiver to the transmitter.
5. The system according to claim 1 , wherein the physical layer control unit sets, based on the first physical layer control information, a transmission data rate of data to be transmitted to the transmitter.
6. The system according to claim 5 , wherein the receiver further comprises a transmission unit configured to transmit, to the transmitter, the data which is set to the transmission data rate and spread by a spread spectrum scheme.
7. The system according to claim 1 , wherein
the transmitter further comprises a second transmission unit configured to transmit, to the receiver, second physical layer control information for the control of the physical layer over the dedicated channel,
the information generation unit generates the second physical layer control information based on the radio channel quality information at a second control timing which is in cooperation with the dedicated channel and generates the first physical layer control information based on the radio channel quality information at the first control timing which fails to be in cooperation with the dedicated channel,
the receiver further comprises a second receiving unit configured to receive the first physical layer control information over the dedicated channel, and
the physical layer control unit controls the physical layer between the receiver and the transmitter based on the first physical layer control information and the second physical layer control information.
8. The system according to claim 7 , wherein the information generation unit generates the second physical layer control information in correspondence with the radio channel quality information.
9. The system according to claim 7 , wherein the physical layer control unit sets, based on the first physical layer control information and the second physical layer control information, a transmission data rate of data to be transmitted to the transmitter.
10. A transmitter comprising:
an acquiring unit configured to acquire radio channel quality information by measuring a radio channel quality when the transmitter receives a signal;
an information generation unit configured to generate first physical layer control information for control of a physical layer based on the radio channel quality information at a first control timing which fails to be in cooperation with a dedicated channel for the control of the physical layer; and
a first transmission unit configured to transmit, to the receiver, the first physical layer control information by selected spreading-code data of a parallel combinatory spread spectrum scheme.
11. The transmitter according to claim 10 , which further comprises a second transmission unit configured to transmit, to the receiver, second physical layer control information for the control of the physical layer over the dedicated channel of physical layer control,
wherein the information generation unit generates the second physical layer control information based on the radio channel quality information at a second control timing which is in cooperation with the dedicated channel and generates the first physical layer control information based on the radio channel quality information at the first control timing which fails to be in cooperation with the dedicated channel.
12. A receiver comprising:
a first receiving unit configured to receive first physical layer control information for control of a physical layer by selected spreading-code data of a parallel combinatory spread spectrum scheme; and
a physical layer control unit configured to control the physical layer between the receiver and a transmitter based on the first physical layer control information.
13. The receiver according to claim 12 , which further comprises a second receiving unit configured to receive second physical layer control information for the control of the physical layer over a dedicated channel,
wherein the physical layer control unit controls the physical layer between the receiver and the transmitter based on the first physical layer control information and the second physical layer control information.
14. The receiver according to claim 13 , wherein the physical layer control unit sets, based on the first physical layer control information and the second physical layer control information, a transmission data rate of data to be transmitted to the transmitter.
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JP2003199295A JP2005039473A (en) | 2003-07-18 | 2003-07-18 | Communication system, transmitter for the system, receiver for the system, and physical layer control method |
JP2003-199295 | 2003-07-18 |
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US10/801,548 Abandoned US20050025098A1 (en) | 2003-07-18 | 2004-03-17 | Communication system, transmitter of the system, receiver of the system, and physical layer control method |
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US20050025079A1 (en) * | 2003-07-18 | 2005-02-03 | Shigeo Terabe | Mobile communication system, radio control station, base station and mobile station for the system, and parameter determination method employing parallel combinatory spread-spectrum scheme |
US20070265757A1 (en) * | 2005-01-24 | 2007-11-15 | Yoshihiro Kawasaki | Transmission power control method and mobile terminal apparatus |
US20080069020A1 (en) * | 2004-07-30 | 2008-03-20 | Andrew Richardson | Signal Transmission Method from a Local Network Node |
US20080069028A1 (en) * | 2004-07-30 | 2008-03-20 | Andrew Richardson | Power Control in a Local Network Node (Lln) |
US20100197336A1 (en) * | 2007-06-19 | 2010-08-05 | Ntt Docomo, Inc. | Transmit power control method, base station apparatus and user apparatus |
US20130243042A1 (en) * | 2012-03-13 | 2013-09-19 | Industry-Academic Cooperation Foundation, Chosun University | Phased spreading scheme-based transmission apparatus and method of operating the same |
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US6847828B2 (en) * | 2000-07-03 | 2005-01-25 | Matsushita Electric Industrial Co., Ltd. | Base station apparatus and radio communication method |
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US20050025079A1 (en) * | 2003-07-18 | 2005-02-03 | Shigeo Terabe | Mobile communication system, radio control station, base station and mobile station for the system, and parameter determination method employing parallel combinatory spread-spectrum scheme |
US7292526B2 (en) * | 2003-07-18 | 2007-11-06 | Kabushiki Kaisha Toshiba | Mobile communication system, radio control station, base station and mobile station for the system, and parameter determination method employing parallel combinatory spread-spectrum scheme |
US8000340B2 (en) | 2003-07-18 | 2011-08-16 | Kabushiki Kaishatoshiba | Parameter determination base station employing PCSS scheme |
US20070268851A1 (en) * | 2003-07-18 | 2007-11-22 | Kabushiki Kaisha Toshiba | Mobile communication system, radio control station, base station and mobile station for the system, and parameter determination method employing parallel combinatory spread-spectrum scheme |
US20080069020A1 (en) * | 2004-07-30 | 2008-03-20 | Andrew Richardson | Signal Transmission Method from a Local Network Node |
US20080069028A1 (en) * | 2004-07-30 | 2008-03-20 | Andrew Richardson | Power Control in a Local Network Node (Lln) |
US8290527B2 (en) * | 2004-07-30 | 2012-10-16 | Airvana, Corp. | Power control in a local network node (LNN) |
US8311570B2 (en) | 2004-07-30 | 2012-11-13 | Airvana Llc | Method and system of setting transmitter power levels |
US8503342B2 (en) | 2004-07-30 | 2013-08-06 | Airvana Llc | Signal transmission method from a local network node |
US8886249B2 (en) | 2004-07-30 | 2014-11-11 | Airvana Lp | Method and system of setting transmitter power levels |
US7702354B2 (en) * | 2005-01-24 | 2010-04-20 | Fujitsu Limited | Transmission power control method and mobile terminal apparatus |
US20070265757A1 (en) * | 2005-01-24 | 2007-11-15 | Yoshihiro Kawasaki | Transmission power control method and mobile terminal apparatus |
US20100197336A1 (en) * | 2007-06-19 | 2010-08-05 | Ntt Docomo, Inc. | Transmit power control method, base station apparatus and user apparatus |
US8391911B2 (en) * | 2007-06-19 | 2013-03-05 | Ntt Docomo, Inc. | Transmit power control method, base station apparatus and user apparatus |
US20130243042A1 (en) * | 2012-03-13 | 2013-09-19 | Industry-Academic Cooperation Foundation, Chosun University | Phased spreading scheme-based transmission apparatus and method of operating the same |
US8767798B2 (en) * | 2012-03-13 | 2014-07-01 | Industry-Academic Cooperation Foundation, Chosun University | Phased spreading scheme-based transmission apparatus and method of operating the same |
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